1. Field of the Invention
The present invention relates generally to a tone generator for use in such apparatuses for generating tones as electronic musical instruments and amusement appliances. More particularly, the present invention relates to a tone signal processing apparatus for suitable in saving the power consumption of these instruments and appliances.
2. Description of Related Art
With the recent enhancement in the performance of tone generators for use in electronic musical instruments for example, the maximum number of sounding channels and the level of operating clock frequencies grow steadily. This inevitably causes an increase in the number of transistors and the number of transistor switching operations in a unit time in tone generator LSIs for example, thereby presenting a problem of the proportionally increased power consumption in these LSIs. Especially, with battery-driven electronic musical instruments, the large power consumption presents a serious problem which must be solved to provide an operating life long enough for the general use of these musical instruments.
With CPUs for use in personal computer for example, a technology is known by which the clock frequency is adjusted in accordance with occasional processing loads. However, this technology has a drawback of complicating the configuration of the clock circuits.